VF480 Install

[xyvyx]

Originally Posted by mfanatic325

Up to 9psi of boost, I got like just under 400rwhp and right at 300rwtq peaks with supposedly an older style supercharger core unit (they say it has to do with the impeller or something ). So they think that until I swap the core unit out, I won't see the 470rwhp and 330rwtq that I should be at. They informed me there are zero changes to the VF570 tune, and so there are no improvements in drivability.

How's your drivability? Part-throttle? Any idle hunt? Do you have an AFR gauge? How do they look during driving?

Mine stutters during driving and has erratic idle hunt every now and then. I've just lived with it for the past few months, as I've been too busy with work to do anything about it anyhow. Looking to get everything ironed out this springtime.

So if a core/impeller swap would bring you up to the full 470rwhp with the identical tune you have now, I would assume the setup you have now would be all kinds of inefficient or otherwise borked. Yes, the ECU is adaptive and can vary fuel trims and timing to reach it's targets... but we're also running w/o the MAF sensor, so it's gotta have some air volumes pre-programmed or something, right?


My drivability is actually pretty darn good. I haven't put it on a track nor dyno, though, so I'm just drivin' around town trying not to grab too much attention. I've still got my OEM resonators, so I'm not as loud as you

part-throttle is pretty stable... sensitive like the pre-install sport mode. I don't use sport mode now, it seems tooo twitchy. But I might try it again.

On startup, there IS about 10-15 seconds of idle hunt... it ping-pongs +/- maybe 600 rpm or so until it settles. If I blip the throttle, it does it again (albeit for a short time) when the rpm comes back down. I think it does this regardless of engine temp, but less in general once it warms up. I'll do a recording of it next week.

I have no external AFR gauge nor sensor. Since those SS cats have an extra bung, I'd like to install one. So all the AFR measurements I have are via TorquePro on my phone. In general, I think they look good, although I think it's a bit low on idle.

My logs are captured at one record/second. I'd like to increase the sample rate, add a few more sensors and make some more controlled runs to see what's going on. I just realized that while I'd been viewing ST/LT fuel trims, they haven't been logged. My logs do have speed, rpm, throttle position, AFR and voltages of the pre/post o2 sensors and a few other things. I'm attaching a couple of them to this post. I think the big file is when I went driving around late at night trying to complete a "drive cycle" for the OBD test.

[mfanatic325]

I just realized since our kits are different, it's like comparing apples and oranges...
The 480 kit uses stock injectors, right?

I believe I'm currently using 500cc injectors or something like that. All I know is it's got orange-ringed top, and required a bit of fuel rail modification for clearance.

I would need to compare drivability with another 570 kit owner

[xyvyx]

Originally Posted by mfanatic325

I just realized since our kits are different, it's like comparing apples and oranges...
The 480 kit uses stock injectors, right?

I believe I'm currently using 500cc injectors or something like that. All I know is it's got orange-ringed top, and required a bit of fuel rail modification for clearance.

I would need to compare drivability with another 570 kit owner

Different injectors AFAIK, but mine aren't stock. They sent me the wrong ones the first time. These also required some slight mods to the fuel rail...

I'm guessing some aspects of our tune are identical (at idle, for instance), but the fuel maps or curves or whatever are different.


I suppose I'll replace the back two O2 sensors and try driving around a whole lot more according to the various drive-cycle guides and see if I can complete any more of the OBD tests. The catalyst test, I assume, uses the rear sensors, but the others are probably based on the main wideband ones. 4 are incomplete, I need to fix at least 3 to pass.

The rear o2 sensors were returning normal voltage values, so that aspect wasn't "turned off"... and some tunes can change the ECU to report "not available" for a given test, at which point the person doing the inspection would ignore them. But VF doesn't do that...

[mfanatic325]

For smogging purposes...I just pay extra

[xyvyx]

So I finally made it back to the dyno.

ugg. I suppose I'll contact VF again in the morning, gather up what data I can, and maybe they'll respond to THIS email.



Just before MY run, the O2 sensor got borked up... so no AFR data for this go round I'll probably try again in the near future, but now begins the fun part of diagnosing WTF is wrong...

[mfanatic325]

Wait...assuming 20% drivetrain loss, you should be getting around 384RWHP [480BHP claim x 0.8]; of which you're getting 371RWHP. Seems okay to me?

What were the BTQ claims for the VF480 kit? That does seem a bit low, considering with NA tune I recall I had 256rwtq peak.

As far as my setup goes, VF says they will no longer cover my s/c core update
So I will be sticking to the supposedly slightly older impeller unless I want to update it through Vortech myself for supposedly around $400.
I'm currently in the process of getting a custom remote tune through Frank Smith. Already got some base datalogging done and hope to have amazing software flashed into the car soon

[xyvyx]

Yeah, my numbers aren't horrible... just lower than expected, even for a Mustang dyno. He stopped the run around 7500 RPM too, so maybe if he hit 8k, the peak would have been a bit higher. But yeah, everyone at the shop was expecting 420, so ~ 370 seemed a bit too low. Tested many bimmers that day & they'd seen many others too.

ie: this dynojet run of the VF480 kit on an M3 resulted in 431HP and 301 ft-lb.

http://farm8.staticflickr.com/7033/6...be1d4de0_o.jpg

That's with similar euro headers & cats. It's pre-VF numbers with the same headers/cats resulted in 298HP and 250 ft-lb, which are pretty close to my original numbers too.

The VF published numbers are 480 and 340 ft-lb.


I see 3 VF480 kits represented on this page:
http://www.flickriver.com/photos/eur...7629208220975/

[mfanatic325]

lol well last I checked, I only had 400RWHP and 330RWTQ with my VF570 kit, so don't be too sad
Granted, I ran on an AWD dyno, but still...

I'll eventually do another dyno run after the new custom remote tune and see if I get closer to 470RWHP & 330RWTQ.

[xyvyx]

ok, after some additional tuning....


so that's:
389HP
296 ft-lb
max boost: 7psi
AFR: ignore that black line... but the 11.8 avg is probably about right.

So at this point, I'm happy.

The VF guys offered to review the logs & see what they could do about the idle / power shortage... but at this point, I think that'd require too much back & fourth to yield the results I got today.

[mfanatic325]

NICE! Congrats on the new power levels! hah, we're about even now. Great for you, super sad for me

Oh well...I got my 570 kit for lower than the price of a new 480 kit, so I can't complain too much. I spent the rest on supporting mods

Hopefully Frank can help me get to the proper power levels as well. I actually got used to this current power level long ago =/

[Jroc]

Its so odd hearing about all these intial problems with these kits. Coming from the VQ35 world, I had a APSTT kit on my G35 making 420whp... eventually 510whp and never had any of these issues or really heard much about them. Even the days of running nitrous on my old viper the days were clear sailing.

Thats the over engineering of a German car for you I guess.

[xyvyx]

Yeah, VF explained to me that part of the problem (w/ OBD readiness at least) was related to how they had to alter the duty cycle of the fuel pump... and that the pump was different than that used on the M3.

And Frank & I were discussing how truly bastardized the Z4Ms were.... like... why did they choose a different ECU when the prior model was working fine!? It's like an experiment gone wrong... and later w/ the E9x models, they used an even newer ECU model that's easier to tune. A Frankenstein suspension... who knows what else!

So combine an oddball ECU with a low-volume vehicle and this is what happens. Our only saving grace is that the S54 motor itself is a known-entity...

[mfanatic325]

Aside from potential hardware inconsistencies and the like, it's pretty safe to assume that the majority of issues arising from going the FI on these cars stem from the difficulty in tuning our stock ECU/DME. The MSS70 is quite picky after all, and amateur tuners just won't cut it